Radiation shield for a safety syringe having a needle sheath

ABSTRACT

A syringe injection shield ( 100 ) is formed primarily from a radio-opaque substance, such as tungsten, to shield medical personnel from exposure to radiation during administration of radiopharmaceuticals to patients. Safety syringes ( 22 ) typically have a needle sheath that can be positioned around a needle ( 24 ) after administration of the radiopharmaceutical. The syringe injection shield of the present invention allows medical personnel to make the syringe “safe” before the used syringe is removed from the syringe injection shield. The syringe is safe when the needle sheath is positioned and locked in place around the needle to reduce the risk of needle stick. The syringe injection shield includes a toggle element ( 110 ) that can assume four different positions as follows: neutral; ready; hold; and release.

BACKGROUND OF INVENTION

Syringes, including those that are used to administer liquidradiopharmaceuticals pose a risk of needle stick. Various safetysyringes have been developed to reduce the risk of needle stick,including the Monoject® sold by The Kendall Company, a business of TycoInternational Ltd., having a place of business at 15 Hampshire St.,Mansfield, Mass. and the SafetyLok® sold by Becton-Dickson and Company(B-D) having a place of business at 1 Becton Drive, Franklin Lakes, N.J.An illustrative example of the Monoject(E) type of technology includesthat disclosed in U.S. Pat. No. 5,156,599 issued on Oct. 20, 1992, whichis incorporated herein by reference. Illustrative examples of theSafety-Lok® technology include that disclosed in: U.S. Pat. No.6,221,052, issued on Apr. 24, 2001, which is incorporated herein byreference; U.S. Pat. No. 6,432,087, issued on Aug. 13, 2002, which isincorporated herein by reference; and U.S. Pat. No. 6,368,303, issued onApr. 9, 2002, which is incorporated herein by reference.

Both the Monoject® and the Safety-Lok® safety syringe have a cylindricalneedle sheath that can be repositioned and locked after administrationof a radiopharmaceutical to surround the needle to reduce the risk ofneedle stick.

Safety syringes with an extendable sheath design are also disclosed in:U.S. Pat. No. 4,994,045, issued to Ranford on Feb. 19, 1991, which isincorporated herein by reference; U.S. Pat. No. 4,998,924, issued toRanford on Mar. 12, 1991, which is incorporated herein by reference;U.S. Pat. No. 4,743,233, issued to Schneider on May 10, 1988, which isincorporated herein by reference; U.S. Pat. No. 5,403,287, issued toTalonn et al. on Apr. 4, 1995, which is incorporated herein byreference; U.S. Pat. No. 5,163,916, issued to Sunderland on Nov. 17,1992, which is incorporated herein by reference; U.S. Design Patent No.313,470, issued to Talonn et al. on Jan. 1, 1991, which is incorporatedherein by reference; and U.S. Design Patent No. 344,355, issued toTalonn et al. on Feb. 15, 1994, which is incorporated herein byreference.

The administration of radiopharmaceuticals can also pose a radiationexposure risk to medical personnel. The use of syringe injection shieldsreduces this risk. Biodex Medical Systems, Inc. of 20 Ramsay Rd.,Shirley, N.Y. sells the Pro-Tec® II syringe injection shield. ThePro-Tec® II syringe injection shield uses tungsten shielding, a leadglass window and fits various disposable syringes. A thumbscrew holdsthe syringe in place.

Biodex also sells the Pro-Tec® III syringe injection shield. ThePro-Tec® III syringe injection shield is produced in two differentmodels. One model is for regular syringes. The other model is designedto function with one or more safety syringes such as the Safety-Lok®sold by B-D or the Monoject® sold by The Kendall Company. There are twoways to remove a used safety syringe from the Pro-Tec® III syringeinjection shield.

One approach is to invert the combination of syringe injection shieldand used safety syringe so that the needle is pointing up relative tothe floor. The release button is then pressed, allowing the used syringeto fall by gravity from the shield. Thereafter, the syringe is typicallyplaced in a pharmaceutical pig (needle down) for transport to a nuclearpharmacy for disposal of the used safety syringe. Unfortunately, theneedle remains exposed during the aforementioned disposal procedure.Approximately 50% of all needlesticks occur after injection and beforedisposal.

Another approach is to position the combination of syringe injectionshield and used safety syringe so that the needle is pointing towardsthe floor. The release button is pressed, allowing the used syringe tobe manually removed from the syringe injection shield. Thereafter, thesyringe is typically placed in a pharmaceutical pig (needle down) fortransport to a nuclear pharmacy for disposal of the used safety syringe.Unfortunately, the needle also remains exposed during the aforementioneddisposal procedure. There is a need for a syringe injection shield thatwill allow a safety syringe to be placed in the “safe” position beforethe syringe is removed from the syringe injection shield. A safetysyringe is in the safe position when the needle is covered by a sheathor other protective element and the sheath is locked in positionrelative to the needle.

There are various ways to place a safety syringe in the safe position,which is well known to those skilled in the art. For example, theMonoject® safety syringe is rotated to a locked position after theneedle has been retracted into the needle sheath. The Safety-Lok® safetysyringe uses a different locking procedure. First, the needle isretracted into the needle sheath, then the barrel is pulledlongitudinally into a locked position. Other safety syringes that usedifferent locking systems may be suitable for use with this invention.

The Pro-Tee® III syringe injection shield has a toggle element that canassume three positions, which are as follows: neutral; ready; andrelease. This prior art toggle element is in the neutral position whenthere is no syringe in the injection shield. The ready position for thisprior art toggle element is when a syringe is in the injection shield.Finally, this prior art toggle element is in the release position whenthe syringe is being removed from the shield.

The prior art toggle element associated Pro-Tec® III syringe injectionshield will not allow the syringe to be made safe prior to removal ofthe syringe from the shield due to the fact that this prior art toggleelement cannot hold a syringe sheath in place so the sheath can belocked in position relative to the barrel and needle.

Many radiopharmaceuticals are injected into a patient's blood vessel. Toconfirm that the needle is properly positioned in the patient's bloodvessel, medical personnel typically pull back on the syringe plunger todraw blood through the needle into the barrel of the syringe. If bloodcannot be seen in the barrel of the syringe, the needle is repositionedand the process is repeated. The radiopharmaceutical is administeredafter the correct position of the needle has been confirmed by thepresence of blood in the syringe barrel. For this reason, prior artsyringe shields typically include a lead glass insert so medicalpersonnel could attempt to see inside the barrel of the syringe while itwas positioned in the syringe shield. Unfortunately, it is hard to seethrough the lead glass into the syringe barrel to confirm the presenceof blood. There is a need for a syringe injection shield that allowseasy visual confirmation of needle placement in a blood vessel. Thepresent invention is directed to overcoming one or more of the problemsset forth above.

SUMMARY OF INVENTION

The syringe injection shield of the present invention includes agenerally tubular member that is sized to receive a safety syringe. Thepresent invention is intended for use with various safety syringesincluding, but not limited to, the Monoject® safety syringe and theSafety-Lok® safety syringe. The tubular member of the present inventionmay be formed in different sizes to accommodate safety syringes fromdifferent sources. The tubular member is typically formed from tungstenor some other radio-opaque substance, which shields medical personnelfrom at least a portion of the radiation emitted from theradiopharmaceutical. A toggle housing is formed in the tubular member tosupport a movable toggle element. Unlike the prior art, the toggleelement has four positions, which are as follows: a neutral position; aready position; a hold position; and a release position. The toggleelement forms a contact point that engages the needle sheath of a safetysyringe when the toggle element is in the hold position. The toggleelement allows medical personnel to make the safety syringe “safe”before the used syringe is removed from the syringe injection shield. Inthe preferred embodiment, the syringe injection shield of the presentinvention is slightly shorter than the safety syringe to make it easierto confirm proper placement of the needle in a blood vessel. However, inalternative embodiments, the length of the syringe injection shieldcould be flush with the end of the safety syringe. These and otheraspects will become apparent to those skilled in the art in light of thefollowing disclosure and accompanying drawings.

BRIEF DESCRIPTION OF DRAWINGS

For a better understanding of the present invention, reference may bemade to the accompanying drawings in which:

FIG. 1 is a section view of a safety syringe inserted into a prior artsyringe injection shield;

FIG. 2 is a perspective view of the syringe injection shield of thepresent invention and a safety syringe, prior to insertion of the safetysyringe into the syringe injection shield;

FIG. 3 is a section view of the syringe injection shield of FIG. 2 andthe safety syringe prior to insertion of the safety syringe into thesyringe injection shield. The toggle element is in the neutral position;

FIG. 4 is a section view of the syringe injection shield and safetysyringe after the syringe has been inserted into the shield. The toggleelement is now in the ready position. The needle is in the extendedposition and is exposed, prior to administration of theradiopharmaceutical to a patient;

FIG. 5 is a section view of the syringe injection shield and safetysyringe of FIG. 4 after administration of the radiopharmaceutical. Theneedle is still in the extended position;

FIG. 6 is a section view of the safety syringe and syringe injectionshield. The needle and syringe barrel are being moved from the extendedposition to the retracted position as shown by the arrow. The toggleelement is still in the ready position;

FIG. 7 is a section view of the safety syringe and the syringe injectionshield. The toggle element is in the hold position. The needle has beenmoved to the retracted position and the finger tabs and syringe barrelare being rotated as shown by the arrow to lock the needle sheath inplace relative to the barrel. The syringe has been “made safe” after theneedle has been moved from the extended to the retracted position andthe barrel has been rotated and locked in place relative to the needlesheath;

FIG. 8 is a section view of the safety syringe and the syringe injectionshield. The toggle element is in the release position. The safetysyringe is being removed from the shield as indicated by the arrow. Thesafety syringe has been “made safe” prior to removal from the injectionshield and the needle is protected by the needle sheath; and

FIG. 9 is a section view of the syringe injection shield after thesyringe has been removed. The safety syringe has been made safe and thetoggle has returned to the neutral position.

DETAILED DESCRIPTION

FIG. 1 is a section view of a safety syringe inserted into a prior artsyringe injection shield. The prior art syringe injection shield isgenerally identified by the numeral 20 and the safety syringe isgenerally identified by the numeral 22.

The safety syringe 22 has a needle 24, not shown to scale, that engagesa luer lock 26, the exact configuration of which is well known to thoseskilled in the art. The luer lock 26 is positioned on one end 28 of thesyringe barrel 30. A plunger 31 fits into the opposite end 34 of thebarrel 30. An elastomeric seal 32 is positioned on one end of theplunger 31 and a push tab 33 is positioned on the opposite end. Fingertabs 36 are formed on the end 34 of the barrel 30, opposite the luerlock 26. The radiopharmaceutical 38 is contained inside the barrel 30between the plunger 32 and the end 28.

A movable needle sheath 40 surrounds the barrel 30 and extends from thefinger tabs 36 to the end 28. The barrel 30 and the needle 24 moverelative to the needle sheath 40 as will be described below. A lockinglug assembly 41 is positioned on the exterior of the end 28 of thebarrel 30 and the interior of the needle sheath 40. Various locking lugassemblies known to those skilled in the art may be suitable for thispurpose. To make the safety syringe 22 safe, the needle 24 is moved fromthe extended position, as shown in this figure to a retracted position,shown in subsequent figures and the barrel 30 is rotated relative to theneedle sheath 40 to lock the needle sheath 40 in position surroundingthe needle 24.

The syringe injection shield 20 includes a generally tubular member 42that is formed from a radio-opaque material such as tungsten to reduceradiation exposure to medical personnel. A lead glass insert 44 ispositioned in the tubular member 42. A toggle housing 46 supports atoggle element 48 that pivots on a shaft 50. The toggle element 48defines a contact point 52 that engages the needle sheath 40. Oppositethe contact point 52 is the release button 54. Below the release buttonis a recess 56 sized to receive one end of a spring 58. A portion 60 ofthe toggle housing 46 forms a spring receiver 61 that receives theopposite end of the spring 58. The spring 58 is under compression whenpositioned as shown in this figure, between the release button 54 of thetoggle element 48 and the spring receiver 61. The purpose of the toggleelement 48 in the prior art syringe injection shield 20 is to hold thesafety syringe 22 in place during administration of theradiopharmaceutical. Unfortunately, the toggle element 48 of the priorart syringe injection shield 20 cannot hold the safety syringe 22 inplace during rotation of the barrel 30 and therefore the safety syringe22 cannot be made safe prior to withdrawal from the injection shield.

The toggle element 48 of this prior art injection shield 20 has thefollowing three positions: neutral; ready; and release. In FIG. 1, thetoggle element 48 is in the ready position. The contact point 52 is incontact with the needle sheath 40. When the release button 54 isdepressed, the prior art toggle 48 is in the release position, notshown. In the release position, the contact point 52 is not in contactwith the needle sheath 40. When there is no safety syringe 22 in theinjection shield, this prior art toggle element 48 is in the neutralposition.

FIG. 2 is a perspective view of the syringe injection shield of thepresent invention and a safety syringe 22, prior to insertion of thesafety syringe 22 into a syringe injection shield. The syringe injectionshield of the present invention is generally identified by the numeral100. The syringe injection shield 100 includes a generally tubularmember 102 that is formed from a radio-opaque material, such as but notlimited to tungsten, to reduce radiation exposure to medical personnelfrom the radiopharmaceutical. The generally tubular member 102 is sizedto receive the safety syringe 22. The tubular member has a distal end104 and a proximal end 106.

A toggle housing 108 is mounted on the tubular member 102 and the togglehousing 108 is sized to receive a movable toggle element 110. A shaft112 is mounted in the toggle housing 108 and the shaft 112 passesthrough the toggle element 110 allowing it to pivot inside the togglehousing 108. Unlike the prior art, the toggle element 110 of the presentinvention has four positions as follows: neutral; ready; hold; andrelease. Each of these four positions will be show in the followingfigures and discussed in sequential operational steps. A lead glassinsert 114 is also positioned in the toggle housing 108.

FIG. 3 is a section view of the syringe injection shield 100 of FIG. 2and the safety syringe 22 prior to insertion of the safety syringe 22into the syringe injection shield 100. The toggle element 110 is in theneutral position. The toggle element 110 forms a contact point 118, anelongate tang 120 and a release tang 122. A recess 124 is formed beneaththe release tang 122 and is sized to hold one end of the spring 128. Aspring holder 126 is formed in a portion of the toggle housing 108 andis sized to hold the other end of the spring 128. When the spring 128 isin position as shown in this figure, the spring 128 is under compressionurging the contact point 118 of the toggle element 110 into the neutralposition. The radiopharmaceutical 38 has already been drawn into thebarrel 30 of the safety syringe 22. To reduce radiation exposure tomedical personnel during administration of the radiopharmaceutical tothe patient, the loaded safety syringe 22 is first placed into thesyringe injection shield 100 as shown in the next figure.

FIG. 4 is a section view of the syringe injection shield 100 and safetysyringe 22 after the syringe has been inserted into the shield. Thetoggle element 110 is now in the ready position. The needle 24 is in theextended position and is exposed, prior to administration of theradiopharmaceutical 38 to a patient. In the ready position, the contactpoint 118 of the toggle element 110 engages the exterior surface of theneedle sheath 40. As previously discussed, radiopharmaceuticals areoften administered into the patient's blood vessel. To confirm properplacement of the needle 24 in the blood vessel, not shown, medicalpersonnel pull back on the plunger 31 as indicated by the arrow to pullblood from the vessel through the needle into the barrel where the bloodor the lack thereof can be observed by the medical personnel. The end 28of the barrel 30 extends beyond the proximal end 106 of the syringeinjection shield 100. To steady the syringe 100 for pullback, the fingertabs 36 are held in a fixed position relative to the syringe injectionshield 100 by the medical personnel.

A portion 120 of the barrel 30 extends beyond the end 104 of the syringeshield 100. This extended portion 120 facilitates observation of thefluid in the barrel 30 by the medical personnel to confirm proper needleplacement. This is easier and faster to see than peering through thedark lead glass 114 into the dark interior of the syringe shield 100.The extended portion 120 is exaggerated in the drawings to emphasizethis feature. In the commercial embodiment, the length of the extension120 is kept to a minimum to reduce radiation exposure. Afterconfirmation of proper needle placement, the plunger 31 is fullydepressed, as shown in the next figure, causing the radiopharmaceuticalto flow from the barrel 30 through the needle 24 into the patient.

FIG. 5 is a section view of the syringe injection shield 100 and safetysyringe 22 of FIG. 4 after administration of the radiopharmaceutical.The plunger 31 has been fully depressed and the seal 32 is in contactwith the end 28 of the barrel 30.

FIG. 6 is a section view of the safety syringe 22 and the syringeinjection shield 100 after the radiopharmaceutical has been administeredto the patient. The needle 24 and barrel 30 have been moved from theextended position of FIGS. 4 and 5 to the retracted position of FIG. 7.

The toggle element 110 is then placed in the hold position as shown inthis figure. In the hold position, pressure is applied by medicalpersonnel to the elongate tang 120 of the toggle element 110 asindicated by the arrow so the contact point 118 will hold the needlesheath 40 in place relative to the injection shield while the fingertabs 36 and the barrel 30 are rotated as indicated by the arrow.

The amount of pressure needed on the toggle in the hold position canvary depending on the size of the elongate tang 120, the configurationof the contact point 118, the locking lug assembly 41 and the type ofsafety syringe 22. However, pressure from about 13 to about 20 poundsand more preferably from about 15 to about 18 pounds on the toggle hasbeen sufficient to hold the needle sheath in place while the barrel isrotated and the syringe is made safe. Optimally, a pressure of about16.5 pounds on the elongate tang will be sufficient while in the holdposition.

FIG. 7 is a section view of the safety syringe 22 and the syringeinjection shield 100. The toggle element 110 is in the hold position inthis figure. In the hold position, pressure continues to be applied bymedical personnel to the elongate tang 120 of the toggle element 110 asindicated by the arrow so the contact point 118 will hold the needlesheath 40 in place relative to the syringe barrel while the finger tabs36 and syringe barrel 30 are being rotated as shown by the circulararrow 150 to properly engage the locking lug assembly 41, not shown.Locking lug assemblies are known in the art. In this figure, the needle24 has been moved to the fully retracted position. The safety syringe 22has been “made safe” after the needle 24 has been moved from theextended to the retracted position and the syringe barrel 30 has beenrotated and locked in place relative to the needle sheath 40. Whenproperly engaged, the locking lug assembly 41 prevents the needle 24from being extended beyond the end of the needle sheath 40. The lockedneedle sheath 40 covers the needle 24 and reduces the risk of needlestick during disposal of the used safety syringe 22.

FIG. 8 is a section view of the safety syringe 22 and the syringeinjection shield 100. The toggle element 110 is in the release position.In the release position, pressure is applied by medical personnel to therelease tang 122 of the toggle element 110 as indicated by the arrow sothe contact point 118 does not touch the needle sheath 40. The safetysyringe is then removed from the shield for disposal. The safety syringe22 has been “made safe” prior to removal from the syringe injectionshield 100 and the needle 14 is protected by the needle sheath 40.

FIG. 9 is a section view of the syringe 22 and the syringe injectionshield 100. The toggle element 110 is in the neutral position. Thesafety syringe 22 has been completely removed from the syringe injectionshield 100 and is ready to be disposed. The needle 24 is protected bythe needle sheath 40 and full use has been made of the features of thesafety syringe 22.

1-12. (canceled)
 13. An injection shield assembly comprising: agenerally tubular member sized to accommodate a needle sheath of asafety syringe, the member having a distal end and an opposing proximalend, the member comprising radiopaque material; and a movable toggleelement designed to pivot relative to the member, the toggle elementcomprising: a first tang extending at least generally out away from anexterior of the injection shield assembly; a second tang disposed atleast generally between the first tang and the proximal end of themember; and a third tang, at least a portion of which is located in asafety syringe accommodating aperture of the injection shield assembly.14. An injection shield assembly as in claim 13, wherein the third tangis substantially tapered.
 15. An injection shield assembly as in claim13, wherein the member comprises a toggle housing, and the toggleelement designed to pivot relative to the toggle housing.
 16. Aninjection shield assembly as in claim 15, further comprising a springdisposed between the toggle housing and the toggle element.
 17. Aninjection shield assembly as in claim 16, further comprising a shaftmounted to the toggle housing and passing through the toggle element,the toggle element being designed to pivot about the shaft.
 18. Aninjection shield assembly as in claim 17, wherein the spring is spacedfrom and does not contact the shaft.
 19. An injection shield assembly asin claim 15, further comprising a lead glass insert positioned in thetoggle housing.
 20. An injection shield assembly as in claim 13, furthercomprising a shaft about which the toggle element is designed to pivot,wherein the first tang extends away from the shaft in a first direction,the second tang extends away from the shaft in a second direction, andthe third tang extends away from the shaft in a third direction.
 21. Aninjection shield assembly as in claim 13 further comprising a safetysyringe having a barrel, a needle, a plunger, and a needle sheath,wherein the needle sheath is disposed about and movable relative to thebarrel, and wherein the member is disposed about at least a portion ofthe needle sheath.
 22. An injection shield assembly as in claim 21,wherein the third tang is in contact with the needle sheath.
 23. Aninjection shield assembly as in claim 22, wherein a length of the memberis shorter than a length of the barrel.
 24. A method of using aninjection shield assembly, the method comprising: inserting a safetysyringe into an injection shield in a manner such that the injectionshield is disposed about a needle sheath of the safety syringe; changinga condition of the safety syringe from a first condition in which aneedle of the safety syringe is exposed for use, to a second conditionin which the needle sheath is substantially disposed about the needle,wherein the changing is accomplished while the injection shield isdisposed about the needle sheath, and the changing comprises applyingpressure to a first tang of a toggle element of the injection shield;and removing the safety syringe from the injection shield, wherein theremoving comprises applying pressure to a second tang of the toggleelement.
 25. A method as in claim 24, wherein the disposing comprisescontacting the needle sheath with the toggle element of the injectionshield.
 26. A method as in claim 24, wherein the changing comprisescontacting the needle sheath with the toggle element of the injectionshield.
 27. A method as in claim 26, wherein the contacting comprisesholding the needle sheath in place relative to the injection shieldwhile a barrel of the safety syringe is rotated relative thereto.
 28. Amethod as in claim 24, wherein the toggle element does not touch thesafety syringe during the removing.
 29. A method as in claim 24, whereinthe changing comprises supplementing the pressure applied to the toggleelement with a spring force.
 30. A method as in claim 24, wherein theremoving comprises imposing a spring force on the second tang in adirection substantially opposite that of the pressure applied.
 31. Aninjection shield assembly comprising: a safety syringe having a barrel,a needle, a plunger, and a needle sheath, wherein the needle sheath isdisposed about and movable relative to the barrel; and an injectionshield comprising: a generally tubular member comprising radiopaquematerial and disposed about at least a portion of the needle sheath ofthe safety syringe; and a movable toggle element designed to pivot abouta shaft of the injection shield relative to the generally tubularmember, the toggle element comprising: a first tang that extends awayfrom the shaft in a first direction; a second tang that extends awayfrom the shaft in a second direction; and a contact point that extendsaway from the shaft in a third direction, the contact point beingdesigned to be moved in and out of contact with the needle sheath of thesafety syringe.
 32. An injection shield assembly as in claim 31, furthercomprising a spring that biases the first tang at least generally towardthe needle sheath and that biases the second tang at least generallyaway from the needle sheath.